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3 years ago

Which feature do all adult echinoderms have?

2 answers:

4 0

The common name to the family member of phylum Echinodermata of marine family is echinoderm. They are usually characterized by a five-fold symmetry, and possess an internal skeleton of calcite plates. They are found at every ocean depth.

The features of all adult echinoderm are:

- They have a five-fold symmetry.

- Body without segmentation.

- Spiny skin.

- Internal skeleton.

- found at every ocean depth.

BigorU [14]3 years ago

3 0

Mhmh they have smellytypes on their bodies so yeah

You might be interested in

Methanol, ethanol, and n−propanol are three common alcohols. When 1.00 g of each of these alcohols is burned in air, heat is lib

KengaRu [80]

Answer:

For methanol: Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

For ethanol: Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

For propanol: Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

Explanation:

Given:

Mass of Methanol = 1.0 g

Mass of ethanol = 1.00 g

Mass of n-propanol = 1.00 g

For methanol:

2 CH₃OH + 3 O₂ ----> 2 CO₂ + 4 H₂O, ∆H₀ = -22.6 kJ/g (negative sign signifies release of heat)

1 g of methanol on combustion gives 22.6 kJ of energy

Calculation of moles of methanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of methanol = 32.04 g/mol

Thus moles of methanol = 1 g/ (32.04 g/mol) = 0.0312 moles

Hence energy in kJ/mol:

Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

For ethanol:

C₂H₅OH + 3 O₂ ----> 2 CO₂ + 3 H₂O, ∆H₀ = -29.7 kJ/g (negative sign signifies release of heat)

1 g of ethanol on combustion gives 29.7 kJ of energy

Calculation of moles of ethanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of ethanol = 46.07 g/mol

Thus moles of ethanol = 1 g/ (46.07 g/mol) = 0.0217 moles

Hence energy in kJ/mol:

Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

For propanol:

2 C₃H₇OH + 9 O₂ ----> 6 CO₂ + 8 H₂O, ∆H₀ = -33.4 kJ/g , (negative sign signifies release of heat)

1 g of methanol on combustion gives 33.4 kJ of energy

Calculation of moles of methanol:

$moles=\frac{Mass(m)}{Molar\ mass (M)}$

Molar mass of methanol = 60.09 g/mol

Thus moles of methanol = 1 g/ (60.09 g/mol) = 0.0166 moles

Hence energy in kJ/mol:

Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

5 0

3 years ago

Help

Jet001 [13]

Answer:

Explanation:

The formation of ion occurs when an atom that is said to be neutral gains or losses electrons.

At the time it gains electrons, it is regarded that a negative ion (anion) is formed.

When it loses electron, it is regarded that a positive ion (cation) is formed.

Atomic number = No of protons and electrons occurring in a neutral atom.

Given that:

Protons = 14

electron = 18

Net Charge = no of proton - no of electron

= 14 - 18

= -4

Mass number = 14 + 15 = 29

So, the chemical symbol = $Si^{-4}$

For ion with

27 proton, 32 neutrons and 25 electrons

Net charge = 27 - 25

= +2

Mass number = 27 + 32 = 59

Thus, the chemical symbol = $Co^{+2}$

6 0

3 years ago

If you have significant concerns about a child's development, you should A. sensitively present your concerns to the family and

Veronika [31]

I think its answer choice A because it would better to talk to their parents first and not take matters into your own hands.

6 0

3 years ago

Read 2 more answers

what the type of solid materials are typically hard, have high melting pionts and poor electrical conductivities

Virty [35]

Answer:

Ionic solids

Explanation: Ionic solids—Made up of positive and negative ions and held together by electrostatic attractions. They're characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl.

7 0

3 years ago

Read 2 more answers

Non-ferrous alloys do not contain a. copper. b. brass. c. gold. d. iron.

Elena L [17]

Iron is the correct answer

4 0

3 years ago

Read 2 more answers